2pc of 8GB PC3-12800 CL11 16c 256x8 DDR3-1333 240pin DIMM. Genuine CMS brand, CMS is one of the most trusted names in the Computer Memory industry and this product carries a Lifetime Warranty from CMS. Compatible with: Compatible with Dell Inspiron 3647 Maximum Memory: 16 GB SOCKETS: 2 MODULES MUST BE ORDERED AND INSTALLED IN PAIRS for Dual Channel mode, if supported. If 4GB is installed, the recognized memory may be reduced to 3.5GB or less (depending on system configuration and memory allocation). Maximum configurations require a 64-bit operating system.